Schools Superintendent William Reimer says he's willing to laugh at a good senior prank. Greased walls? Locks filled with glue? No problem.

Hundreds of Madagascar hissing cockroaches? Not funny at all.Classes at Ottawa Hills High School in this Toledo suburb were canceled Friday after custodians found hundreds of the giant insects, many about 2 inches long and an inch wide, creeping along in the hallways.

"Sometimes, they've really been creative and good kinds of pranks, but they haven't been destructive and made us close down," Reimer said. "We will absolutely prosecute to the fullest."

Students weren't allowed in the building while exterminators worked to clean up the mess throughout the morning. Hopes of holding classes in the afternoon were frustrated because the creatures kept turning up in classrooms and containers.